A wide variety of diagnostic or therapeutic procedures involve introducing an access device into a patient's body. The access device provides an access lumen, which is used to introduce diagnostic or therapeutic instruments into the patient. A general objective of such access devices is to minimize the cross-sectional area of the access lumen while maximizing the available space for the diagnostic or therapeutic instrumentation.
One exemplary environment where access devices are used is the urinary tract of a patient. Access devices are introduced into the urinary tract to perform, e.g., ureteroscopy, including stone extraction, stricture treatment, or stent placement. To remove bladder stones, e.g., a cystoscope is often placed into the bladder through the urethra, and subsequently, access devices such as a ureteral sheath or a catheter are inserted through the cystoscope. These sheaths/catheters, when deployed, provide a working channel for medical devices to access portions of a patient's body to perform desired procedures. For example, a lithotripter and a suction device may be inserted through the catheter to first break-up a urethral stone into smaller pieces and then, extract it from the body.
Those in the art will appreciate that positioning and guidance of such an interventional device may be accomplished by introducing a camera, a light source, or similar devices into the body. Each of these devices may be inserted into the body lumen through working channels in the cystoscope. The sizes of such devices may be limited by the smaller dimensions of a patient's urinary tract. The primary surgical task, such as extracting kidney stones, dictates the tools that must be introduced through the working channels, leaving scant room for auxiliary devices such as cameras and light sources.
Therefore, there exists a need for an improved access device that includes visualization devices while maintaining a substantial cross-sectional area to allow passage of suitable surgical tools.